Piston ring



Patented Aug. 6, 1929.

UNITED STATES 'PATENT OFFICE.

ALLEN W. MORTON, .OF BALTIMORE, MARYLAND, ASSIGNOR TO THE AMERICAN HAM# MERED PISTON RING COMPANY, OF BALTIMORE, MARYLAND, A CORPORATION or MARXLAND.

having drainage openings extending therefrom to the interior of the piston.

'lhe present structure, while effecting proper drainage, also provides a structure which tends to do away with the so-called piston slap which often lnheres 1n venglnes where the piston and rlngs become worn and is also a means of increasing the tension in the piston ring, particularly in the oil ring, without injurious results. A

An embodiment of my invention is disclosed in theannexed drawings wherein:

Figure l is a side elevation, partly in section, of a portion of a piston showing a ring arrangement embodying my invention,

Figure 2 a transverse horizontal 'sectional view on the line II-II of Figure 1, Figure 3 a detail sectional View of a portion of the piston and oil ring on an enlarged scale,

Figure 4 a plan view of the inner spirirt'gv or expander ring,

Figure 5 a detail sectional view of such element upon anienlarged scale,

Fignre 6 a f ace view of said element, and

Figure 7 a. detail view illustrative of a modified forni of perforation formed in the inner ring.

Referring to the drawings, Figures 1 to 6 both inclusive, 1 denotes a portion of a piston having the usual rings 2 and 3 located in groovest and 5, respectively, adjacent the head of the piston and above the oil ring.l

The oil ring in the broader aspect of the invention may be of any approved form so long as it is of theventilated t I prefer, however, to employ a ring of t e form shown wherein the body 6 is-rectangular in cross section and is provided with a series of slotsor openings 7 extending from the inner to the outer face, said slots being wider at the outer than at the inner yface of the ring, as best-seen in Figure 2.

The outer cylinder contacting face of the production of a' ventilated oil ring compris-v rrs'roN RING.

Application 1ed May 19, 1928. Serial No. 279,155.

ring will also be provided withl two grooves 8 and 9 located one to each side. of theslots .and extending entirely around the ring.

The edgesof these grooves, it maybe stated serve to scrape the oil from the cylinder surface 10, and likewise tend to distribute sufiicient oil over' the cylinder face'to insure proper lubrication.

Ring 6, which is seated in a groove 11, is formed of any suitable material and normally expands so as to contact thecylinder wall. To centralize the ring with reference to the piston, and hence with reference to the cylinder, I employ an inner expander element 12, which, for the purpose of brevity, I- term an" expander ring. Said member is produce-d from' spring strip metal and is preferably bent to the contour (in plan) shown in Figures 2, 4 and 5.

As will be seen upon reference to' said views the ring is formed with a series of long flat or straight sections 13 and a series of short fiat sections 14. The longer flat sections 13 may be of any desired length but the length of the short sections 14 will besuch vas to be shorter than the radius X of the curved sections 15 which interconnect the various By thus contouring the expander ring it4 will assume the position shown in Figure 2 with reference to the' inner face of ring 6 and the rear or inner face of the groove 11 providing suicient zones of contact between the elements to insure the exertion of an outward and equal expansive force against the oil ring 6.

Furthermore, it is to be no'tedthat the ezt-g pander ring presentano sharp bends or" anglesin its make-up. .This is of advantage in that no incipient line of fracture is presented or produced and further there will be little or no appreciable wear betweenthe two rings. Where a sharp angle or bend is produced in the expander ring,!it will not only cause excessive unit pressure between 'the expander ring and the piston ring at these vbends or points of contact, but will also wear and cut into the outer rin thereby weakening it. More frequently, owever, the expander will itself break at these sharp corners or bends.

Ring 12 has formed therein a pluralityof openings 16, shown in Figures 1, 3, 5 and 6 as being round." Preferably but a single opening will be produced in the short sections 14 in order to not unduly weaken the same and in fact the openings in the short.A sections may be omitted without unduly cut-' ting down the efficiency of the drainage of the device.

The form of the openings through the eX- panderring is immaterial and they may, for instance, be elongated as shown at 17, Figure 7. v

The' inner wall of groove ll-or that portion of the 'piston which lies inward of the groove-is ported lfor the passage of oil. Such porting may be effected as by anelonf gated slot 18 as shown in Figures 1 and 3 andat the left hand portion in Figure 2,- or by a series of openings 19 as illustrated at the right in Figure '2. -Ineither case passage for the inward Adrainage of oil removed from the cylinder by the ring '6 is afforded.

It is thought that the operation ofthe structure will be appreciated by those skilled in the art but a brief rsum will be given.

Invariably after piston rings have been in service for some time the edges of the rings become rounded due to wear, and when in certain instances the pistons and rings t comparatively loosely in the cylinder, the outer or cylinder contacting faces of the rings wear most pronouncedly convex. When such a condition arises it is obvious that only the center line of any particular ringl is in continuous contact with the walls of the cylinder.

Now, assuming that the piston is moving downwardly, in Figures 1 and 3, then the ring 6 will tend to scrape the excess oil from the face of the cylinder, and its action will be somewhatas follows: A certain amount of oil will be scraped from the walls'of the cylinder by the lower edge of the ring 6 and an additional amount of oil will be .removed from the cylinder face by the upper edge of groove 9, and that which seeps past these two scraping edges just referred to 4will be caughtand scraped from the face of the cylinder by the upper edge of the slots or openings 7. The oil thus collected will pass through the-openings 7 in the "piston ring,

j thence through the openings 16 in the inner expander ring, and thence through the, slot 18, or openings 19, in the piston tothe interior thereof. On a reverse movement of` the ring 6. Thus the ring 6 is held in close contact with the walls of the cylinder at all points,and with sufiicient tension to scrape oil from the walls of the cylinder at all speeds, and'fu'rthermore, by virtue ofthe expander ring 12, the piston is centralized Within the cylinder and the tendency to rock or move fromvside to side is lessened to a most marked degree. Of course, full' and sufficient drainage of the oil which is scraped from the walls of'the cylinder by the slots or openings 7, in the piston ring 6, is pro: vided by means of the openings 16 in the expander ring and the ports 18 or 19 in the piston.

lVhat isl claimed is:

I l. As a new article of manufacture an expander ring formedof thin sheet metal, said ring in outline having a series of flat faces, a second series of flat faces intermedi-- ate the first, said second series-.being relatively short as compared. tothe first or longer ones, and said'long and short yfaces being connected by curved sections the radii of which is greater than the length of the short fiat sections.

2. As aLl-new article of manufacture an expander'ring formedy of thin sheet metal, said ring in outline having a series of fiat faces, a second series of flat faces inter1nedi ate the first, .said secondl series being relatively short as :omparedztoe the first or longer ones, and said long and short faces being connected by curved sections the radii of which is greater` than the length of the short flat sections, said longer sections at least being provided with perforations extending therethrough.

In testimony whereof I have signed my name to this specification.

ALLEN W. MORTON.- 

